KR20080045758A - Illuminator - Google Patents

Abstract

The present invention relates to an illuminator (10, 30, 40) comprising a spatial light modulator (14) including an array of elements (16) each adapted to selectively transmit incoming light without altering the direction of the light, or alter the direction of incoming light; a lamp (12) arranged to illuminate the modulator; a lens (20, 42) for directing unaltered light from the modulator onto an illumination surface (24); and means for forwarding essentially all light altered in direction by the modulator towards the illumination surface.

Description

Lighting equipment {ILLUMINATOR}

The present invention relates to a lighting device. In particular, the present invention relates to an illumination device that includes a light modulator that enables projection of illumination effects, such as images, patterns, text, etc., onto an illumination surface.

Prior art image projection devices use light from a lamp (liquid crystal display (LCD), etc.), which is transmitted through a light valve or modulator, wherein the image of the modulator is projected onto the projection surface using a projection lens.

The modulator generally includes an array of addressable elements or pixels to produce an image. In one type of image projection device, each pixel is optional to transmit incoming light (without changing its direction) or to change the incoming light's direction (eg by scattering), as disclosed, for example, in document US5622418. Is adapted to. The transmitted light can then be projected by the projection lens onto the projection surface to form an image, where at least a portion of the scattered light is absorbed to form a high contrast image. In the system disclosed in US5622418, the entrance pupil of the projection lens operates to remove some of the scattered light in the liquid crystal light valve to increase the contrast of the projected image. Thus, part of the light from the lamp is lost. This is acceptable in display applications but not in lighting applications.

It is an object of the present invention to overcome this problem and to provide an improved apparatus for lighting applications.

This and other objects that will become apparent from the following descriptions include: a spatial light modulator comprising an array of elements each adapted to either deliver incoming light without changing the direction of light, or to redirect the incoming light; A lamp arranged to emit a modulator; A lens for inducing unchanged light from the modulator to the light projecting surface; And means for essentially delivering all the light redirected by the modulator toward the light projecting surface.

It is understood that the present invention can provide a luminaire for generating a specific lighting effect by redistributing some of the light from the lamp, which is redirected by the modulator (instead of absorbing or otherwise intercepting this light as in the prior art). In this case, the loss of light is significantly reduced, especially at high angles. Light may be transmitted directly to the light transmitting surface or through the lens.

The transmission of light can be done in a variety of ways.

In one embodiment, the delivery means comprises a reflector adapted to reflect light redirected by the modulator toward the light transmitting surface. Preferably, the reflector is formed in a tapering tubular shape, with the modulator positioned at the narrow end of the tube, the wide end of the tube facing the light transmitting surface, the cross section of the tube being essentially consistent with the shape of the modulator. Thus, even light starting from the modulator at a high angle can be reflected towards the light projecting surface.

In another embodiment, the delivery means comprises a segmented lens wherein the lens is a segmented lens that directs unchanged light from the modulator to the light projection surface ("light directing lens"). It is formed as part of. Preferably, the segmented lens has a central first portion and a peripheral second portion, the first portion having a different focal length and / or optical axis than the second portion. The light guide lens is preferably formed of a central first portion, which essentially receives all unaltered light from the modulator. Thus, in the case of light transmitted unaltered through the modulator, an image is formed by the central portion of the segmented lens. On the other hand, for light modified by the modulator, due to the difference in the focal length and / or optical axis of the two parts, the light originating from the center part is different from the light originating from the peripheral part, thereby causing the image formation at a position on the projection surface Will induce. This makes it possible to achieve the desired contrast of the formed image / pattern. Preferably, the segmented lens has a diameter that allows the peripheral second portion to essentially intercept all light redirected by the modulator and direct the light towards the light transmitting surface. Segmented lenses can be used with or without the reflectors described above.

The luminaire may further comprise a second lens positioned between the lamp and the modulator. The second lens has a different diameter and / or different focal length than the first lens. This allows more possibilities for beam shaping. The second lens can be used with the reflector described above and / or with the segmented lens described above.

The illuminator may further comprise a non-absorbing aperture positioned between the modulator and the first lens. Preferably, the non-absorbing aperture is adapted to change the direction of light falling towards it, preferably to switch towards the light transmitting surface. Such an aperture can be made of scattering material, which scatters incoming light in any direction, or in a particular direction. Alternatively, the aperture can be refractive or diffractive. Such apertures may include micro lens arrays, blazed gratings, ruled gratings, phase gratings, and the like.

In one embodiment, the aperture has an aperture so that the light from the lamp is focused in the aperture, for example by a second lens, a reflector in or associated with the lamp, or a combination of both. Holes herein should be interpreted as openings or transmissive portions of the aperture that transmit light without changing the direction of the light. Thus, light transmitted through the modulator without changing the direction is passed through the hole, while light from the element of the modulator, where the path (i.e. the direction) changes, does not pass through the hole, It will fall into the scattering (or refraction or diffraction) region. In this way the effect of the light path bypass can be amplified and / or the light can be directed in a particular direction which allows for higher contrast and more control over beam formation.

In another embodiment, the non-absorbing aperture has locally adjustable light transmission properties. This gives much more control over beam formation.

The direction of incoming light can be changed by the modulator using effects such as scattering, reflection, or diffraction. The modulator may be, for example, a pixilated liquid crystal cell.

This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings which show preferred embodiments of the invention.

1 is a schematic side view of a lighting device according to an embodiment of the present invention;

2 is a schematic side view of a lighting device according to another embodiment of the present invention, and

3 is a schematic side view of a lighting device according to another embodiment of the present invention.

In the drawings, like elements are designated by like reference numerals.

1 is a schematic side view of a lighting device 10 according to an embodiment of the present invention. The illuminator 10 comprises a lamp 12, a spatial light modulator 14 comprising an array of light modulation elements 16, a control device 18 for receiving data and controlling the modulator 14 accordingly, and The lens 20 is included.

The lamp 12 may be, for example, a light emitting diode light source.

Each element 16 is optionally adapted to transmit incoming light (ie without changing the direction of the light, ie the path), or to change the direction of the incoming light depending on its selected state. Light modulator 14 may be, for example, an active matrix, multiplexed or pixylated liquid crystal cell with direct electrical addressing, and the change of direction, ie path, may be electrically controllable liquid crystal effects such as scattering, refraction, or diffraction. Can be achieved using Various liquid crystal devices suitable for the present invention will be apparent to those skilled in the art.

The lighting device 10 further includes a reflector 22. The reflector 22 of FIG. 1 is shown in cross section and is formed as a tapering tube, the cross section of the tube essentially coinciding with the shape of the modulator 14, the modulator 14 being located at the narrow end of the tube, The wide end of is directed towards the light transmissive surface 24.

In operation of the luminaire 10, the lamp 12 emits a modulator 14. The state of the element 16 of the modulator 14 is controlled by the control device 18 based on the data received regarding an image or pattern or something else that can be projected. Depending on what state the device is in, each device 16 either passes the incoming light straight away or redirects the incoming light. Light transmitted immediately is shown by a relatively thick line, and redirected light is shown by a thin line. By way of example, element 16a transmits light while element 16b changes the direction of light by, for example, scattering.

Light transmitted straight through the modulator 14 is projected by the lens 20 onto the light transmissive surface 24 to form lighting effects such as images, text, and the like.

On the other hand, the light redirected by the modulator 14 passes through the lens 20 to the light transmissive surface 24 or is reflected by the reflector 20 toward the light transmissive surface 24. As shown, even light present in the modulator 14 at a steep angle is directed towards the light transmissive surface 24. Thus, essentially all of the light redirected by the modulator 14 is directed towards the light transmissive surface 24, with the desired light effect on the light transmissive surface 24 with the light transmitted unchanged through the modulator 14. To form. The simulation shows that the area on the light emitting surface corresponding to the scattering (eg) area on the modulator has a lower intensity, but the reduced intensity is redistributed to other areas of the light emitting surface.

2 is a schematic side view of a lighting device 30 according to another embodiment of the present invention. In addition to that disclosed in FIG. 1, the luminaire 30 further includes a second lens 32 positioned between the lamp 12 and the modulator 14. Lens 32 focuses the light from lamp 12. In FIG. 2, the focal point of the lens 32 coincides with the focal point of the first lens 20 such that the beam transmitted through the modulator 14 without any change in direction is essentially parallel by the first lens 20. Facing the light transmissive surface 24. On the other hand, the light redirected by the modulator 14 is directed toward the light projecting surface 24 through the first lens 20 or reflected by the reflector 22 toward the light projecting surface 24. In another configuration (not shown), the first lens 20 has a focal length corresponding to the distance to the modulator 14, so that the image of the modulator is projected onto the projection surface 24.

Optionally, the illuminator 30 may include a non-absorbing aperture 34 positioned between the modulator 14 and the first lens 20. The stop 34 may be, for example, a scattering stop. In FIG. 2, the aperture 34 includes a transparent hole 36. The aperture 34 is positioned away from the second lens 32 by a distance corresponding to the focal length of the second lens 32, so that the modulator 14 does not change any direction when the luminaire 30 operates. The beam passing through the beam is focused into the hole 36. This then results in these beams passing through the aperture 34 to the first lens 20. The size of the aperture 36 can be determined by the quality of the lamp (spread of the light bundle). On the other hand, in the modulator 14, the direction or direction of light “missing” the hole 36 is scattered by the aperture 34. Some of this light is scattered straight toward the first lens 20 and / or the light transmissive surface 24, and some is scattered toward the reflector 22, which reflects the light in succession towards the light transmissive surface 24. Thus, essentially all the light redirected by the modulator 14 is directed towards the light transmissive surface 24, with the light transmitted unchanged through the modulator 14, to the desired light effect on the light transmissive surface 24. To form. The simulation shows that by the aperture 34 and the aperture 36, the contrast of the formed light effect is increased so that there is little light loss at the light transmitting surface. Also in an alternative configuration, the modulator 14 may be located at the focal length of the first lens 20 such that the image of the modulator is projected onto the light transmissive surface 24. In this configuration, the first lens 20 has a focal length farther than the second lens 32.

It should be noted that the light focused from the lamp may alternatively be achieved by reflector means provided in or associated with the lamp, or by a combination of such reflector means and a second lens.

Instead of a non-absorbing aperture with a hole, a non-absorbing aperture with locally adjustable light transmission properties can be used. That is, at least one portion of the aperture may be selected to transmit the light without changing its direction, and at least one portion of the aperture may be selected to change the direction of incoming light hitting the portion (s). Such an aperture can be realized by a liquid crystal cell, which can locally address and exhibit electrically controllable effects such as, for example, scattering, diffraction, or refraction.

3 is a schematic side view of a modulator 40 according to another embodiment of the present invention. Compared to that disclosed in FIG. 1, the modulator 40 includes a second lens 32 and a segmented lens 42.

The segmented lens 42 of FIG. 3 comprises a central first portion 44 having a first focal length and a peripheral second portion 46 having a second focal length different from the first focal length. do. Alternatively, the two portions may have the same focal length but different optical axes from each other.

Lenses 32 and 42 are adapted to the first portion 44 in the center of the segmented lens 42 where the beam transmitted through the modulator 14, with no change in direction, is present in operation of the modulator 40. It is also arranged to be incident. This may be accomplished by selecting the appropriate size, focal length, and / or position, etc. for the lenses 32 and 42. The beam incident on the central first portion 44 can then be projected onto or directed toward the light transmissive surface 24 to form an image, pattern, or the like. On the other hand, for light modified by the modulator 14, the light reaching the central portion 44 is different from the light reaching the peripheral portion 46 (either straight or after being reflected by the reflector 22). Image formation will be induced at a location on the light transmissive surface 24 due to the difference in the focal length and / or optical axis of the two parts. Thus, essentially all of the light redirected by the modulator 14 is directed toward the light transmissive surface 24 and with the light transmitted unchanged through the modulator 14, the desired light on the light transmissive surface 24. Form the effect.

In FIG. 3, the focal point of the second lens 32 coincides with the focal point of the central portion 44 of the segmented lens 42, and the projection surface 24 is essentially parallel to the optical axis 48 of the luminaire. Headed. In an alternative configuration, the modulator 14 may be located at the focal length of the central portion 44 of the segmented lens 42, such that the image of the modulator is projected onto the projection surface 24. In addition, the segmented lens can be located near the focal length of the second lens 32 to ensure that essentially all light that is not redirected by the modulator 14 is incident on the central portion 44. In this case, the quality of the lamp, ie the spread of the light bundle, can determine the size of the central portion 44.

It should be noted that both the reflector 22 and / or the second lens 32 may be omitted in the embodiment shown in FIG. 3. In the former case, the segmented lens 42 preferably transmits light by intercepting most of the light whose peripheral second portion 46 has been redirected by the modulator 14. It has a diameter that allows it to face away.

Those skilled in the art will recognize that the present invention is not limited in any way to the preferred embodiments described above. On the contrary, various modifications and changes are possible within the scope of the appended claims.

Claims (14)

As luminaires 10, 30, 40, Forwards incoming light unchanged, or To change the direction of the incoming light A spatial light modulator 14, optionally including an array of adapted elements 16, respectively; A lamp (12) disposed to project the modulator; A lens 20 for inducing unchanged light from the modulator to the light projecting surface 24; And Means (22, 42) for transmitting essentially all of the light redirected by the modulator toward the projection surface Lighting device comprising a. 2. The luminaire according to claim 1, wherein said means for transmitting comprises a reflector (22) adapted to reflect light redirected by said modulator toward said projection surface. 3. The reflector of claim 2, wherein the reflector is formed as a tapering tube, the modulator is located at the narrow end of the tube, the wide end of the light is directed towards the light-transmitting surface, and the cross section of the tube is Preferably illuminating essentially with the shape of the modulator. The luminaire according to any one of claims 1 to 3, wherein the means for transmitting comprises a segmented lens (42), and the lens for inducing light is formed by a portion of the segmented lens. . 5. The segmented lens of claim 4, wherein the segmented lens has a central first portion 44 and a peripheral second portion 46, the first portion having a different focal length and / or optical axis than the second portion. Lighting equipment having. The illuminator of claim 5, wherein the lens for inducing light is formed by a first portion of the center portion. 7. A lighting device as claimed in any preceding claim, further comprising a second lens (32) positioned between the lamp and the modulator. 8. The luminaire of claim 7, wherein said second lens has a different diameter and / or different focal length than said light guide lens. 9. An luminaire according to any one of the preceding claims, further comprising a non-absorbing aperture (34) positioned between the modulator and the lens for guiding the light. 10. A luminaire according to claim 9, wherein said non-absorption aperture is adapted to redirect the incoming light and to preferably transmit it towards said projection surface. 11. An luminaire according to claim 9 or 10, wherein said non-absorbing aperture has a hole (36) and light from said lamp is focused in said hole. 11. A lighting device according to claim 9 or 10, wherein said non-absorbing aperture has a locally adjustable light transmission characteristic. The illuminator of claim 1, wherein a direction of the incoming light is changed by the modulator by any one of scattering, refraction, and diffraction. The illuminator of claim 1, wherein said modulator is a liquid crystal cell.

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